K2CO3/H2O in [omim][BF4] ionic liquid: A green medium for efficient room-temperature synthesis of N-substituted 1,4-benzoxazin-3-ones
A medium consisting of K2CO3 and H2O in [omim][BF4] ionic liquid (IL) was used to synthesize N-substituted 2H-benzo[b][1,4]oxazin-3(4H)-one derivatives from their corresponding o-aminophenols and 2-bromoalkanoates. As a result, chemoselective formation of benzoxazinones in high yields has been observed at room temperature. After the reactions and separation of the products, the IL was recovered and successfully reused in subsequent reactions without significant loss of activity.
Sharifi, Ali,Barazandeh, Mehdi,Abaee, M. Saeed,Mirzaei, Mojtaba
p. 933 - 938
(2012/10/29)
Copper-catalyzed one-pot synthesis of 2H-1,4-benzoxazin-3-(4H)-ones from 2-(o-haloaryloxy)acyl chlorides and primary amines
A facile and efficient Cu(I)-catalyzed one-pot synthesis of 2H-1,4-benzoxazin-3-(4H)-one derivatives has been developed. The condensation between 2-(o-haloaryloxy)acyl chlorides and primary amines followed by Cu(I)-catalyzed intramolecular C-N bond coupling afforded a variety of 2H-1,4-benzoxazin-3-(4H)-ones in good to excellent yields. Diversified substitutents on the 4-position could be conveniently introduced. ARKAT-USA, Inc.